1. Field of the Invention
The present invention relates to a method for producing a photosensitive printing plate, and more particularly to a method for producing a photosensitive printing plate including steps of applying matting agent on the surface of the moving continuous photosensitive printing plate and winding the continuous photosensitive printing plate into a roll.
2. Description of Related Art
In a conventional method for producing a photosensitive printing plate, a photopolymerizing mixture, which is composed of a chemical compound including an ethylene type double bond which can addition-polymerize, a photopolymerization starting agent, an organic high molecular compound, and a thermal-polymerization prohibiting agent, is applied on a metal support such as an aluminum plate. The photosensitive printing plate is covered with a film of a desired original image and is exposed, and thereby, the photopolymerizing mixture of exposed areas polymerizes and hardens. Then, the photopolymerzing mixture of unexposed areas is dissolved and removed. Thus, a hardened relief image is formed on the printing plate.
On the other hand, Japanese Patent Provisional Publication No. 51-111102 discloses a photosensitive printing plate on which matting agent is applied such that fine unevenness patterns are formed on the surface of the photosensitive printing plate, thereby improving efficiency of the vacuum adhesion of the film of the original image onto the surface of the photosensitive printing plate. The matting agent is applied on the moving continuous photosensitive printing plate (hereinafter referred to as web), which is wound into rolls by a winding apparatus.
In the conventional method for producing the photosensitive printing plate, however, in the roll of the wound web, pressure excessively increases on a part of the web which is wound in the inner part (the vicinity of the core) of the roll during the winding, and thereby, the surface of the mat layer formed on the web of the inner part is flattened.
If the surface of the mat layer is flattened, the efficiency deteriorates of the vacuum adhesion of the original film onto the surface of the photosensitive printing plate. Moreover, the pressure applied on the web which is wound in the inner part of the roll is absorbed by the flattening of the mat layer, and a gap is produced between turns of the web due to gravitation. Then, the gap moves to the outer part of the roll during the winding, and thereby a winding disorder occurs.